1. Field of the Invention
The present invention relates to an intraocular lens assembly, and more particularly to an improved posterior chamber intraocular lens assembly which, after surgical affixation within the eye, is further anchored in the eye by natural ingrowth of a tissue of the iris of the eye.
2. Description of the Prior Art
The prior art is well aware of artificial intraocular lens assemblies which are surgically introduced into the human eye to replace the natural lens of the eye. One of the common reasons for removing the natural lens of a patient is a condition of lenticular disease known as a cataract. The prior art has developed a large variety of lens assemblies for surgical implantation either in the anterior chamber or attached to the iris of the eye.
Generally speaking, anterior chamber lenses of the prior art are placed between the iris and the cornea, and rely upon a precise size measurement to wedge the lens into a permanent position. The implantation of some of the artificial intraocular lens assemblies requires surgical incision or suturing to the iris. Other lens assemblies are kept in an operative position within the eye by a plurality of loops which embrace the iris and therefore "clip" the lens assembly to the iris. A recent posterior chamber lens, the SHEARING lens, is held in a relatively fixed operative position by spring like properties of a number of strands composed of plastic material, see U.S. Pat. No. 4,159,546.
For further detailed description of specific intraocular lens assemblies, reference is made to the following U.S. Pat. Nos. 3,925,825; 3,922,728; 3,971,073; 3,673,616; 3,913,148; 3,906,551; 3,994,027; 3,866,249; 3,986,214 and 3,991,426.
Although the implantation of artificial intraocular lens assemblies have become accepted by the medical profession, the artificial intraocular lens assemblies of the prior art can suffer from certain disadvantages such as dislodgment from their initial operative position as a result of post operative movement of the patient's eye.
It is readily appreciated by those skilled in the art, that in order to obtain optimal results a compromise must be found between the relative strength of affixation of the lens to the eye which could become a source of undue irritation, or tissue errosion and the necessity to keep the lens in an operative position within the eye.
U.S. Pat. No. 4,073,015 describes an intraocular lens mounting system wherein a plurality of loops extend substantially laterally from a light refracting lens body. Fibrous material is attached to the outer edges of the loops in areas where the edges come into contact with the iris. The loops affix the lens to the iris, and the subsequent ingrowth of the tissue of the iris further anchors the loops to the iris. U.S. Pat. No. 3,458,870 describes a corneal lens implant wherein a holding member for the optical lens is surgically implanted into the cornea. The holding member has a plurality of holes into which the ingrowth of the corneal stroma is purported to occur to further anchor the corneal implant to the cornea.
The improved artificial lens assembly mountings of the present invention which may be utilized in anterior chamber as well as in posterior chamber lens assemblies represent a further significant advancement.